25/05/2020
Benefits of adhesive bonding in Exterior Thermal Insulation Systems
For thousands of generations, human beings have tried to preserve the heat inside their homes. Many of the inventions and improvements in construction have focused their efforts on this area. And, after many failed systems, we have achieved a more sustainable method of achieving thermal insulation from the outside.
Imagine that you have to rehabilitate a building in the old town (as long as it does not have a protected facade) of a provincial capital. You have looked for the simplest and most effective method that also enhances the value of the building. And so you have found the ETICS system, a method that promises all of the above and more.
The ETICS system, or Exterior Thermal Insulation Systems, responds to that basic need: to rehabilitate a home without harming its residents in the least. Buildings in large cities, which want to improve in energy saving and aesthetics, could use this innovative model to start a new life both inside and outside their structures.
Exterior Thermal Insulation Systems, a quick look
As you know, the ETICS system consists of placing an insulating material attached to the wall by means of adhesive or mixed (adhesive and mechanical) fastening. Thanks to the fact that the insulating material is fixed directly to the wall, producing continuous insulation along the façade, the appearance of thermal bridges in the building is avoided. Thus we put an end to energy losses and temperature transfer between the interior and exterior of the house.
It thus responds to the economic axis of sustainability in many ways, because it also eliminates damage (it eliminates cracks, fissures and guarantees the disappearance of humidity) and it complies with fire regulations according to the CTE (as it is a material that is highly resistant to fire). In addition, maintenance is minimal, as it only needs simple revisions every five years.
Many buildings in need of renovation choose the ETICS system because of its easy application and comfort for residents
What about the other two pillars of sustainability? It is also respectful of the environment because, by conserving the temperature of the interior, it reduces the need for heating (up to 30% savings in energy, adding two or three degrees of difference (remember that, for each additional degree of heating, the bill increases by up to 8%) and the CO2 emissions that this entails. An advantage that helps to improve the environmental certification of the building such as LEED, BREAMM…
As far as people are concerned, the ETICS system offers insulation against noise pollution. What about its installation and maintenance? It does not occupy useful space inside the house and nothing has to be done from the inside. This maintains the quality of life of the inhabitants of the structure. These two advantages also have a lot to do with the fixings you have decided to incorporate.
Fixing the ETICS system: which one should I choose
Two types of fixing materials are usually used: mechanical and adhesive. This means that, to fix the panel to the façade, a cementitious adhesive can be used attached to the mechanical anchorage or a chemical adhesive attached to the mechanical anchorage
If we focus on new construction, the ETICS chemical bonding foam can be one of the fastest bonding systems on the market. It allows the installation of the insulating panels in just 30 minutes, unlike cementitious adhesives, greatly increasing the pace of the work, achieving results much faster. Thanks to the good planimetry of the facades of new construction, yields of 10 m2 will be achieved in only 30 minutes.
In the case of rehabilitation of existing facades, since the support will be uneven and with errors in its planimetry, this adhesive has the facility to correct the unevenness up to 3 cm in the first 15 minutes of its installation. This express installation also reduces the inconvenience to the neighbors who live in the building that is being rehabilitated because the installation time is reduced from being able to make the anchorage in two hours compared to two days.
Even so, the key to a good fixation in these Thermal Insulation Systems for the Exterior is the adhesive that we are going to use. And here there is also a typology to consider.
Two of three adhesive fixings in the ETICS system
The function of the adhesive is paramount, not only by gripping the insulation material on the facade, it also restricts the expansion, contraction and compression of the insulation and adjusts its flatness. According to its nature, there are three types, although we are going to focus on two, because the dispersion adhesive is usually used on wood walls or supports with wood fibres, while the other two are useful for a greater number of insulation and supports.
The adhesive fixing is optimal and is combined with mechanical fixing in facade rehabilitation
On one side is the adhesive cement. It is used on mineral supports, such as brick or concrete, and can be applied to any type of insulation. This limits the rehabilitation of some facades, although a large number are made of these materials. It is possible to work it in adverse climates with rainfall, and this adhesive is prepared by mixing the materials in a bucket, mixing with water. Its use at present is, above all, because it corrects the less uniform areas of the surface, filling possible gaps and also influences its competitive price.
Think of that great facade of a building in the center of your city, in the middle of April, with a rainy climate that does not favor the mixing of materials that result in adhesive cement. Also add the minimum 48 hours of curing required. It can take up to a week to finish the facade, resulting in an inefficient method for what is supposed to be the ETICS system, faster and easier than other systems.
Our commitment to adhesive bonding
To solve the problems of the two previous ones (low versatility and preparation time) we have the ETICS adhesive foam. This third type is of universal application for all types of supports (wood, concrete, brick, glass, metal…) and for all types of EPS insulation. The most common format is high density, low expansion foam.
We return to that facade of your city in the middle of April, during that week in which it has only stopped raining one day. Well, because it needs no preparation and the initial grip is very fast, in just three seconds, it is the perfect method to work.
But there is more: its great malleability and possibility of rectification makes the foam perfect for the possible flaws and inconveniences that incorporate the old facades, always respecting the classic aesthetics. In addition, the foam corrects up to 3 cm of differences in levels of the facade.
Rehabilitation for sustainability
We have already seen that the three types of adhesive fasteners respond to the environmental axis promised by the ETICS system. But the Exterior Insulation Systems that want to enhance the other axes should use the adhesive foam, because not only is it faster, universal and easy to apply in any circumstance (therefore, more economical) but it also requires fewer complements to be applied (hindering less in the street and making the life of the residents easier).
The rehabilitation of a building is done in defence of an improvement in quality in all these aspects. And you, which adhesive would you choose?
Sources: IADE, Calor y Frío, Calor y Frío
